Effects of Dietary Vitamin C and Vitamin E On the Performance of Laying Hens in the Humid Tropics

Effects of Dietary Vitamin C and Vitamin E On the Performance of Laying Hens in the Humid Tropics.

ABSTRACT

This study which lasted for 52 weeks investigated the effects of dietary Vitamin C (L- ascorbic acid) and Vitamin E (dl- alpha tocopheryl acetate) on the performance of laying hens in the humid tropics.

A total of 240 twenty-four week old Golden Neslink pullets were randomly selected from a flock of 550 birds and randomly divided into sixteen treatments of 15 pullets. The birds were initially vent examined to ensure that they were at point of lay before commencing the study.

Each pullet was randomly assigned to a previously cleaned and disinfected cage measuring 49 x 35 x 42cm at a stocking density of one bird per cage.

Four dietary levels of Vitamin C: 0, 200, 400, and 600mg Kg-1 basal diet were combined with four dietary levels of Vitamin E: 0, 125, 250 and 375mg Kg-1 basal diet in a 4 x 4 factorial arrangement in a Completely Randomized Design. All management principles were observed.

Dead birds were promptly removed for autopsy when the need arose. At the end of the study, three birds were selected per treatment for haematological investigation.

Blood samples were collected from the wing vein of the birds using a 3ml syringe and a 23-gauge needle and placed in micro tubes with Ethlene diamine tetra acetic acid (EDTA) as anti- coagulant for determining the haematological values.

The samples were cooled to 4 ^oC, using icepacks and transferred to the laboratory within 12h of blood collection. The economic implication of the study was then calculated. Data obtained were subjected to analysis of variance (ANOVA) using SPSS.

The mean minimum and maximum indoor temperatures recorded during the study ranged between 18.3-25.0 ^oC and 27. 15-34 ^oC respectively while the RH values lay between 53.0 and 88.9%. These were well outside the zone of thermo neutrality for laying hens.

Results obtained indicated that, there were highly statistical differences (P < 0.01) between Vitamin C and Vitamin E treated birds for hen day production (HDP), feed intake (FI), feed conversion ratio (FCR), Haugh unit score (HUS), , egg weight (EWT) and incidence of cracked eggs.

The treatment, T7 (400mg vitamin C + 125 mg vitamin E Kg^-1 basal diet) was superior to all the other treatments and had the highest values for HDP  (85.45±1.15),  FI  (113.15±0.56),  HUS  (96.27±0.47),  and  EWT  (69.11±1.52).

These   values were however, statistically similar (P > 0.05) to T8 (600mg Vitamin C + 125 mg Vitamin E Kg^-1 basal diet). The lowest values for HDP (42.33±1.43), FI (65.42±0.61), HUS   (75.50±2.10) and EWT (54.50±1.15) were observed in T1 (Controls).

The synergism between Vitamin C and E is different from the sum of the two vitamins applied separately. Loss in body weight, incidence of cracked eggs and mortality were statistically higher (P < 0.01) in T1 (controls) than vitamin treated birds which showed no significant (P > 0.05) differences.

With Vitamin C supplementation, birds on T3 (400 mg Vitamin C kg^-1 basal diet) were superior to T2 (200 mg Vitamin C kg^-1 basal diet) and T4 (600 mg Vitamin C kg^-1 basal diet). Similarly, for Vitamin E supplementation, birds on T9 (250 mg Vitamin E kg^-1 basal diet) were statistically different (P < 0.01) from T5 (125 mg Vitamin E kg^-1 basal diet) and T13 (375 mg Vitamin E kg^-1 basal diet).

For haematological values investigated T7 recorded the highest values for RBC (4.11±0.15×10⁶), Hb (8.80±0.31g/dl), and WBC (18300±519.62/mm³) and these were statistically similar (P > 0.05) to T8 but highly statistically different (P < 0.01) from the rest of the treatments.

There was highly significant interaction (P < 0.01) in the net income/dozen of eggs that accrued from the study. T7 had the highest net income/dozen egg of N1, 627.11±28.68 while the least net income (N560.50±32.12) was generated from T1.

This work therefore upholds that vitamins C and E act in synergy, and that the combined effects of the two antioxidants are additive, immunomodulatory, anti- parasitic and economical.

TABLE OF CONTENTS

TITLE PAGE.. ii

CERTIFICATION………… iii

DEDICATION…….. iv

ACKNOWLEDGMENTS………. v

ABSTRACT…….. vii

TABLE OF CONTENTS……….. viii

LIST OF TABLES…….. xiii

LIST OF FIGURES…………. xv

LIST OF PLATES…….. xvii

CHAPTER ONE

• INTRODUCTION…………………. 1
• SPECIFIC OBJECTIVES……….. 4
• JUSTIFICATION OF THE STUDY…………. 4

CHAPTER TWO

• REVIEW OF RELATED LITERATURE……………………… 6
• ANATOMY AND COMPOSITION OF THE AVIAN EGG………….. 6
  • The Shell……………………. 6
  • Shell Membranes………………. 6
  • Germinal Disc…………….. 6
  • White (Albumen)…………. 8
  • Chalaza……………………. 8
  • Yolk membrane……… 8
  • Yolk…………….. 8
  • Air Cell…………….. 8
• THE AVIAN PHYSIOLOGY OF EGG PRODUCTION……… 11
  • The Male Reproductive System………. 11
    • Deferent duct………… 11

2.2.1.2   Testes and sperm….. 12

• Female Reproductive System…………. 12
  • Ovary………….. 12
  • Oviduct…………………….. 17
  • Uterus (shell gland) and eggshell quality……… 20
  • Vagina…………………….. 21
  • Cloaca……………. 21
• Egg Quality…….. 21
  • Physical and internal measures of egg quality……….. 24

2.2.3.2   Factors influencing egg shell quality………. 27

• STRESS IN POULTRY………… 33
  • Common Causes Of Stress In Birds……… 34
  • TYPES OF STRESS………… 34
  • Physiological Mechanism Of Stress Regulation……… 35
    • The Stage of alarm reaction e. Neurogenic…….. 37
    • The Stage of resistance or adaptation….. 37
    • Stage of exhaustion……….. 39
    • Physiological indicator of stress in poultry…….. 41
    • Physiological reactions of birds to high ambient temperatures…….. 42
    • Physiological effects of panting…….. 48
    • Adaptation……………… 49
  • HOT WEATHER MANAGEMENT OF POULTRY.. 49
    • Stocking Density…………. 49
    • Bird Handling…………. 49
    • Water Temperature……….. 49
    • Feeding Time…… 52

2.4.5.      Feed Stimulation….. 52

• Nutrition………. 52
• Housing………….. 55
  • Naturally ventilated houses……… 55

2.4.7.2   Power ventilated houses……… 59

2.4.7.3.  Evaporation cooling…………. 60

• REPORTED EFFECTS OF HOT WEATHER ON PRODUCTION ATTRIBUTES OF POULTRY………. 61
  • Effect Of Hot Weather On Egg Production…….61
  • Effect Of High Ambient Temperatures On Voluntary Feed Intake……… 62
  • Effect Of Hot Weather On Feed Conversion Efficiency……….. 65
  • Effect Of High Environmental Temperature On Egg Shell Quality……… 65
  • Effects Of Hot Weather On Body Weight Gain……………… 67
  • Effect Of Hot Weather On Egg Weight, Fertility And Hatchability….. 68
  • The Avian Blood 68
    • Blood plasma 69
    • Red blood cells (RBCs) 69
    • Haemoglobin 70
    • Blood platelets 70
    • White blood cells (WBCs) 70
    • Effect of Heat Stress On Hematocrit Values…………………….. 75
    • Effect Of Heat Stress On Blood Electrolytes In Birds…………… 76
  • Effect Of Hot Weather On Disease Prevalence And Mortality……… 77
• TECHNIQUES FOR REDUCING EFFECT OF HOT WEATHER ON POULTRY     78

• Vitamin C 78
  • Chemical structure 78
  • Properties of Vitamin C 78
  • Functions of Vitamin C 84
  • Absorption, transport, and disposal of Vitamin C………………… 86
  • Endogenous production of Vitamin C………………….. 87
  • Ameliorative effects of dietary Vitamin C (L-ascorbic acid) on heat stressed chickens….. 87
• Vitamin E……………. 95
  • Chemical structure…………………………… 95
  • Properties Vitamin E……. 97
  • Sources of Vitamin E…………… 97
  • Biosynthesis of Vitamin E……….. 97
  • Functions of Vitamin E……………. 104
  • Effects of dietary Vitamin E (dl-alpha tocopheryl acetate) on the performance of heat stressed laying hens.106
• Feed Restriction And Heat Stressing Early In Life….. 109

CHAPTER THREE

• MATERIALS AND METHODS……………….. 110
• LOCATION AND DURATION OF EXPERIMENT………… 110
• MANAGEMENT OF EXPERIMENTAL ANIMALS………….. 110
• EXPERIMENTAL DESIGN AND LAY OUT………. 111
• STUDY PROCEDURE……………………… 115
• MEASUREMENT OF PARAMETERS…………… 115
  • Hen Day Production……………….. 115
  • Average Daily Feed Intake…… 115
  • Loss in Body Weight……………….. 116
  • Feed Conversion Ratio….. 116

3.5.5.     Average Egg Weight (g)……… 116

• Haugh Unit Score (HU)……………… 116
• Shell Thickness (mm)………. 116
• Cracked Eggs…………… 116
• Mortality Rate (%)…………….. 117
• Economic Analysis of Production……….. 117
• Haematological Studies……………. 117
• Meteorological Records……………….. 118
• Proximate Analysis of Experimental Diet…………… 118

3.5         STATISTICAL ANALYSIS………. 120

CHAPTER FOUR

4.0          RESULTS AND DISCUSSION……. 121

4.1.        METEOROLOGICAL RECORDS………. 121

• EFFECTS OF DIETARY VITAMINS C AND E ON PRODUCTION ATTRIBUTES OF GOLDEN NESLINK LAYING HENS IN THE HUMID TROPICS…………. 121
  • Hen Day Production……………… 121

4.2.1      Feed Intake………. 128

4.2.3.     Feed Conversion Ratio, FCR……………. 131

• Egg Weight………… 132
• Shell Thickness……. 135
• Cracked eggs… 141

4.2.7.     Haugh unit score (HUS)…….. 145

4.2.8      Loss In Body Weight (BWT)… 148

4.2.9.      Mortality……… 151

• Haematological Values Of Laying Hens Supplemented With Vitamins C And Vitamin E Under Humid Tropical Conditions. 155
• Economic Analysis of Egg production… 181

CHAPTER FIVE

• SUMMARY, CONCLUSION AND RECOMMENDATIONS……………………….. 201
• SUMMARY……………………….. 201
• CONCLUSION………………….. 202
• RECOMMENDATIONS…………… 202

REFERENCES….204

APPENDICES.. 240

INTRODUCTION

Human diets in tropical countries such as Nigeria are most often protein-poor, both quantitatively and qualitatively (Okeke et al., 1985; Ojewola, et al., 2004). For instance, the contemporary average per capita protein consumption in Nigeria is estimated at 7-10g (Oluremi et al., 2008; Okuneye, 2002).

This estimate falls far below the FAO (1997) recommendation of 35g/caput/day. Meanwhile, it should be borne in mind that the Nigerian population on the other hand, continues to rise.

Current demographic figures show that the total head count overshoots 140 million at a 3.0% annual growth rate (BBC News, 2006; Nigerian News, 2006), without a corresponding livestock population to match (FAO, 2005).

To stabilize this situation, no improvement could be made in this country without an increase in food crops, livestock and fish farming. Even then, from the point of view of quality protein consumed, animal proteins by far outweigh proteins from crop sources (Obioha, 1992).

Regrettably, there is a perennial low intake of animal products such as meat, milk and eggs in Nigeria (Onyimonyi, 2002). Unfortunately, these animal products are the major sources of high quality proteins.

The implication is that, the nutritional status of the Nigerian population and economic development are inextricably linked.

This is a clear indication of the inability of the traditional system of animal agriculture to meet the protein needs of Nigerians creating an avenue for protein malnutrition to persist!

REFERENCES

Abdallah, A.G., Harms, R.H. and El-Husseiny. O. (1993). Various methods of measuring shell quality in relation to percentage of cracked eggs. Poult. Sci., 72:2038-2043.

Abdelkarim, M., Harris, G.C. Jr. and Waldroup, P.W. (1985). The influence of dietary energy level on broiler performance under moderate and hot-humid tropical climates. Poult. Sci.,   64:    I     (Abstr).   Accessed  at http://www.britannica.com/EBchecked/topic/190049/epinephrine. on 27 May.

Abdel-Wahab, M.F., Abdo, M.S., Megahed, Y.M., Attia, M,E., Farrahat, A.A. (1977). The effect of vitamin C supplement on the thyroid activity of chickens using ¹²⁵I. Nutr. Abstr. and Rev. Serv., B 47 (8): 554 No. 4165.

Abutu, J.A. and Ugwu, S.O.C. (2005). A comparison of the physical and biochemical characteristics of table eggs laid by exotic and local hens. Unpub. PGD project. University of Nigeria, Nsukka.

Aduku, A.O. and Olukosi, J.O. (1991). Animal products handling and processing in the tropic. Abuja: Living Book Series, G.U. Publications. Pp.201-219.